fix: support MCP 2 timeout values

src/google/adk/tools/mcp_tool/session_context.py

@@ -18,6 +18,7 @@
 from contextlib import AbstractAsyncContextManager
 from contextlib import AsyncExitStack
 from datetime import timedelta
+from importlib.metadata import version
 import logging
 from types import TracebackType
 from typing import Any
@@ -36,8 +37,10 @@
 
 _T = TypeVar('_T')
 
+_MCP_MAJOR = int(version('mcp').split('.', 1)[0])
 
-def _read_timeout(seconds: Optional[float]) -> Optional[timedelta]:
+
+def _read_timeout(seconds: Optional[float]) -> Optional[timedelta | float]:
   """Converts a timeout in seconds to the type ``ClientSession`` expects.
 
   ADK carries every timeout as float seconds. MCP SDK 1.x wants a
@@ -52,6 +55,8 @@ def _read_timeout(seconds: Optional[float]) -> Optional[timedelta]:
   """
   if seconds is None:
     return None
+  if _MCP_MAJOR >= 2:
+    return seconds
   return timedelta(seconds=seconds)
 
 

tests/unittests/tools/mcp_tool/test_session_context.py

@@ -24,6 +24,7 @@
 
 from google.adk.features import FeatureName
 from google.adk.features._feature_registry import temporary_feature_override
+from google.adk.tools.mcp_tool import session_context
 from google.adk.tools.mcp_tool.session_context import _format_exception
 from google.adk.tools.mcp_tool.session_context import _read_timeout
 from google.adk.tools.mcp_tool.session_context import SessionContext
@@ -1023,3 +1024,14 @@ def test_zero_is_a_real_timeout_not_a_missing_one(self):
 
   def test_fractional_seconds_survive(self):
     assert _read_timeout(0.5) == timedelta(seconds=0.5)
+
+  def test_mcp_2_uses_float_seconds(self, monkeypatch):
+    monkeypatch.setattr(session_context, '_MCP_MAJOR', 2)
+
+    assert _read_timeout(30) == 30
+    assert _read_timeout(0.5) == 0.5
+
+  def test_mcp_1_uses_timedelta(self, monkeypatch):
+    monkeypatch.setattr(session_context, '_MCP_MAJOR', 1)
+
+    assert _read_timeout(30) == timedelta(seconds=30)